A wireless body area network (WBAN) includes wearable computing devices which are often used to monitor a patient's vital signs (e.g., blood pressure, heart rate, oxygen levels, electrocardiogram (ECG) data, etc.) in a hospital's telemetry ward. A wireless personal area network (WPAN) is a short-range network covering a range of about forty feet. The WPAN can be used as a gateway by the WBAN to reach telemetry stations and/or repeaters, so that the monitors can communicate their information to a centralized location.
Because of the proximity of hospital beds to one another, WBANs operate in close proximity. This close operating proximity can cause interference between the WBANs. Interference can also occur between to sensor devices of the same WBAN. One solution addressing this interference has been to implement a time domain multiple access (TDMA) based protocol to avoid collisions between packets sent by sensor devices that belong to the same WBAN so as to minimize packet loss (and information degradation). The TDMA approach can use a common schedule among WBANs. In some implementations, WBANs can sense the existence of interfering WBANs, and exchange their TDMA schedules to define when a WBAN can transmit without being exposed to interference generated by another WBAN.
Because of the critical nature of the information being transmitted by a patient's WBAN, the data outage specifications can require a transmission success rate of, for example, about 95%. Conventional monitoring networks address interference by retransmitting a data message multiple times to increase the transmission success rate. However, retransmitting data can result in stale data that might exceed a delay requirement.
For patient health monitoring, the issues of data latency and data outage can be extremely problematic. Vital sign monitoring is an important part of patient care since the general or particular health of the patient is determined, in part, through measurement and interpretation of key physiological indicators. Such physiological data, however, is only of use if it is transmitted in a timely and accurate manner. Transmission of such vital sign data must therefore be timely and be transmitted at a high rate of success in order for a WBAN to be beneficial to patient monitoring.